Diffraction from Sharply Peaked Waves As an Ocean Surface Scattering Mechanism

Abstract

We have investigated the role of sharply peaked waves as a major Ocean scattering mechanism for radar. We constructed a prototype 3-dimensional wedge-like wave shape and analyzed how it scatters. Using results from the theory of the statistical geometry of the Ocean surface we estimate how may such wedges there are per unit area, as a function of sea conditions. Taking into account a directional distribution of the wedges, we estimated the total radar cross section due to wedge diffiraction effects. At large incidence angles wedge diffraction appears to be able to account for a significant amount of the radar cross section on the Ocean surface. This work is a major change from previous work in two ways. First, the wedge-like wave shape used here is a more realistic representation of sharply-peaked waves and second, the scale-size and spatial density of the wedge-like waves is computed directly from the wave-height spectrum.